Santa Ana’s or just very warm…what’s going on??

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Today is a great day to look at the differences in the weather between our two of our three office locations: Incline Village (Lake Tahoe) and San Diego County.

The Tahoe Basin is seeing unseasonably warm with high temperatures nearing 60 degrees. San Diego County is even warmer with highs today in the low to mid 80’s, but with strong Santa Ana winds.

Both areas are under high pressure aloft, bringing descending, warming air, and clear skies. But the Tahoe Basin is in the center of the high, with a weak pressure gradient and light winds, while San Diego County is squeezed between a low over Baja California and the high to the north. The resulting strong pressure gradient is bringing strong cold east winds across eastern San Diego County. As the winds cross the mountains, the air warms and dries dramatically, and some of the atmospheric waves formed over the mountains make it to the ground, with incredibly strong gusts. In San Diego County this morning, winds gusted to 76 mph at Sill Hill (9 miles southwest of Julian, Ca). See the graphic from NWS San Diego.

Winds will stay light in the Tahoe Valley the next few days…while they will be diminishing in San Diego County.

Long range models show the next chance of rain for the region will arrive around the middle of next week.

 

Jim Purpura
Director, Weather Forecasting
purpura@weatherextreme.com